The present invention relates to an ink jet recording apparatus comprising: a recording unit including an ink jet recording head and an ink cartridge that are mounted on a carriage which moves in the width of a recording sheet; and a casing body, wherein the main body for accommodating the recording unit and having an opening for exchanging ink cartridges which is provided on a part of the moving path of the carriage. In particular, the present invention pertains to a control technique for moving the carriage to the exchange opening formed in the casing body.
Since owing to the development of personal computers graphic processing can be performed comparatively easily, a demand exists for recording apparatuses that can, for example, output high quality hard copies of color images displayed on screens. In response to this demand, recording apparatuses in which ink jet recording heads are mounted are being produced. Since during printing the noise made by such ink jet recording apparatuses is comparatively low, and since the apparatuses can deposit small dots at a high density, the apparatuses are presently being used to perform a variety of different types of printing, to include color printing.
Such an ink jet recording apparatus comprises: ink jet recording heads, for receiving ink from ink cartridges; and a paper feeding mechanism, for moving a recording sheet relative to the recording head. During the printing process, the recording heads, which are carried along by a carriage while it moves the width of a recording sheet, eject ink droplets that are deposited on the recording sheet. Mounted on the common carriage are a black recording head for ejecting black ink, and color recording heads for ejecting yellow, cyan and magenta inks, for example, so that not only can text be printed in black ink, but also full color printing can be performed by changing the ratio of the inks to be ejected.
Since the ink jet recording heads perform printing by pressurizing ink in a pressure generating chamber and then ejecting that ink through nozzles as ink droplets, a print failure can be caused by an increase in the viscosity of the ink or the solidification of the ink due to the evaporation of a solvent through nozzle orifices, by the attachment of dust particles, or by the entry of air bubbles.
Therefore, the ink jet recording apparatus further comprises a capping member for sealing the nozzle orifices of the recording head while printing is not being performed, and a cleaning device for cleaning a nozzle plate as needed. The capping member not only serves as a lid for protecting ink at the nozzle orifices from being dried out when printing is not being performed, but when the nozzle orifices are clogged, it also seals a nozzle plate and induces a flow of ink through the nozzle orifices so as to resolve an ink ejection failure that is caused by the clogging of the nozzle orifices due to the solidification of ink, or due to air bubbles that have entered an ink channel.
The forcible ink suction and discharge process, which is performed to prevent the clogging of the recording head or the entry of air bubbles into an ink channel, is normally called a cleaning operation. The cleaning operation is begun when printing is restarted after the apparatus has been halted for a long time, or when a user manipulates a cleaning switch to resolve the degrading of the quality of a recorded image. For this process, ink droplets are drawn out through the nozzle orifices by the application of a negative pressure, and a cleaning member, constituted by an elastic rubber plate, wipes the surface of the recording head.
In this type of recording apparatus, the capping member and the cleaning member are located at the end of the path along which the carriage is moved, and when the carriage has been moved to the end (home position), the face of the recording head wherein the nozzle orifices are formed can be sealed by the capping member.
Further, in a recording apparatus of this type, a black ink cartridge and color ink cartridges are prepared for supplying ink to the black recording head and to the color recording heads. A common recording apparatus of this type is so designed that individual cartridges can be attached to and removed from a carriage on which the recording heads are mounted.
When, for example, an ink cartridge of the above described recording apparatus has been emptied and is to be replaced, it is employed a control method to move the carriage to a position other than the home position. This is done in order to avoid the following problems. If the ink cartridge can be replaced while the recording head is sealed by the capping member, the undesirable removal of an ink cartridge that has not yet been emptied can be easily performed. Further, the force exerted when an ink cartridge is exchanged adversely affects the capping member, resulting in an increase in the pressure in the sealing cap that destroys an ink meniscus in the nozzle and results in a printing failure.
Therefore, a recording apparatus is provided which is so designed that, in the casing body accommodating the recording device, an opening for exchanging ink cartridges is formed at a position other than the home position, whereat the capping member is located, and when ink cartridges are to be replaced, a carriage is moved to the exchange opening.
In, for example, Japanese Patent Publication No. 9-70962A, there is disclosed the structure of a recording apparatus wherein an exchange opening is formed in a casing body. According to this recording apparatus, when the printer cover at the top of the casing body is opened, this action is detected and the carriage is moved to the exchange opening.
Furthermore, in Japanese Patent No. 2716891, there is disclosed a structure wherein an exchange opening is formed in a casing body containing the main body of a recording apparatus. According to this recording apparatus, the carriage is moved to the exchange opening upon the manipulation of an operating key that releases the printer cover and that places the apparatus in an ink cartridge exchange mode.
However, according to the first related recording apparatus, each time the cover at the top of the casing body is opened during printing, the printing process is halted and the carriage is moved to and halted at the exchange opening. Throughput is therefore reduced.
Further, according to the second related recording apparatus, the operating key for releasing the cover and for placing the apparatus in the ink cartridge exchange mode must be manipulated in order to exchange ink cartridges, thus rendering the exchange job complex and providing usability that is less than excellent. In addition, whenever erroneous manipulation of the operating key occurs the printing process is halted and the carriage is moved to and halted at the exchange opening, and throughput is reduced, as in the first related art.
To resolve the above shortcomings, it is one objective of the present invention to provide an ink jet recording apparatus having excellent operability in which a carriage can be automatically move toward an exchange opening when, for example, ink cartridges must be replaced.
In order to achieve the above object, there is provided an ink jet recording apparatus comprising: an ink jet recording unit including a recording head having nozzle orifices from which ink drops are ejected, an ink cartridge for supplying ink to the recording head, and a carriage on which the recording head and the ink cartridge are mounted and being moved in a width direction of a recording sheet; a casing body for accommodating the ink jet recording unit, the casing body having an opening formed along a part of path on which the carriage is moved in order to exchange the ink cartridge therethrough, and a cover member being closed to cover the opening and being opened to expose the opening; ink end detection means for detecting the ink end of the ink cartridge; cover state detection means for detecting whether the cover member is opened; and carriage control means for controlling a position of the carriage so as to move toward the opening when the ink end detection means detects that ink has been exhausted and when the cover state detection means detects that the cover member is opened.
The apparatus further comprises capping means for sealing a surface of the recording head on which the nozzle orifices are formed and for drawing ink out through the nozzle orifices by the application of negative pressure generated by negative pressure generating means. The opening may be situated other than a home position whereat the capping means are provided.
In the apparatus, the ink end detection means may include cartridge detection means for detecting whether the ink cartridge is mounted on the carriage, and counting means for counting the amount of ink ejected by the recording head which is reset when the cartridge detection means detects that a new ink cartridge is mounted. The ink end detection means determines that the ink has been exhausted when a value held by the counting means reaches a predetermined count.
Alternatively, it may be configured that the ink end detection means detects conductivity in the ink cartridges through electrodes embedded therein, and makes a determination that the ink has been exhausted based on the detected conductivity.
In the apparatus, the carriage control means may move the carriage toward the home position when the cover state detection means detects that the cover member is closed.
The apparatus may further comprise cleaning control means for driving the negative pressure generating means to apply the negative pressure into the capping means which seals the surface of the recording head on which the nozzle orifice are formed. The cleaning control means is activated when the cover state detection means detects that the cover member is closed and the cartridge detection means detects that a new ink cartridge has been mounted on the carriage.
In the apparatus, the cartridge detection means may have a flag indicating whether the ink cartridge is mounted on the carriage, which is turned into ON state when the ink cartridge is removed from the carriage, and is returned into OFF state after the cleaning operation for the new ink cartridge is terminated.
The apparatus may further comprise: instruction input means operated by an operator for inputting an instruction to exchange the ink cartridge; and operation detection means for detecting an operation state of the instruction input means. The carriage control means moves the carriage toward the opening when the operation detection means detects that the instruction input means is operated for a predetermined time period or longer.
According to the present invention, there is also provided an ink jet recording apparatus comprising an ink jet recording unit including a recording head having nozzle orifices from which ink drops are ejected, an ink cartridge for supplying ink to the recording head, and a carriage on which the recording head and the ink cartridge are mounted and being moved in a width direction of a recording sheet; a casing body for accommodating the ink jet recording unit, the casing body having an opening formed along a part of path on which the carriage is moved in order to exchange the ink cartridge therethrough, and a cover member being closed to cover the opening and being opened to expose the opening; instruction input means operated by an operator for inputting an instruction to exchange the ink cartridge; operation detection means for detecting an operation state of the instruction input means; and carriage control means for controlling a position of the carriage so as to move toward the opening when the operation detection means detects that the instruction input means has been operated for a predetermined period or longer.
The apparatus may further comprise cover state detection means for detecting whether the cover member is opened. When the cover state detection means detects that the cover member is opened while the carriage is moving, the movement of the carriage is halted.
According to the present invention, there is also provided an ink jet recording apparatus comprising: an ink jet recording unit including a recording head having nozzle orifices from which ink drops are ejected, an ink cartridge for supplying ink to the recording head, and a carriage on which the recording head and the ink cartridge are mounted and being moved in a width direction of a recording sheet; a casing body for accommodating the ink jet recording unit, the casing body having an opening formed along a part of path on which the carriage is moved in order to exchange the ink cartridge therethrough, and a cover member being closed to cover the opening and being opened to expose the opening; instruction input means operated by an operator for inputting an instruction to exchange the ink cartridge; operation detection means for detecting an operation state of the instruction input means; cover state detection means for detecting whether the cover member is opened; and carriage control means for controlling a position of the carriage so as to move toward the opening when the operation detection means detects that the instruction input means has been operated for a predetermined time period or longer, and the cover state detection means detects that the cover member is opened.
The above apparatuses may further comprise alarm means to be driven when the operation detection means detects that the instruction input means has been manipulated for the predetermined time or longer.
In the apparatus, audio alarm means, visual alarm means or means for generating an alarm by driving a mechanical part of the apparatus is employed as the alarm means.
In the apparatus, the recording head and the ink cartridge in the ink jet recording unit may be separately provided. Alternatively, the head and the cartridge may be integrally provided.
In the thus arranged ink jet recording apparatus, when the ink end detection means detects that the ink in an ink cartridge has been exhausted, and when the cover member is opened, the carriage is automatically moved to the exchange opening that is formed in the casing body. As a result, the ink cartridge mounted on the carriage located at the opening can be exchanged.
In this casing body, since the opening for exchanging ink cartridges is located at a position other than the home position whereat the capping means is provided, the erroneous removal or insertion of an ink cartridge is prevented when the recording heads are sealed by the capping means. Thus, the destruction of an ink meniscus due to an increase in pressure in a cap does not occur, and a printing failure can be prevented.
When the cover member on the casing body is closed, the carriage is moved to the home position in accordance with a signal produced by the cover state detection means, and the nozzle formation face of the recording head is sealed by the capping means
Furthermore, when the ink cartridge detection means detects that an ink cartridge is attached to the carriage, the negative pressure generating means is driven to draw out ink. As a result, the ink suction operation can be performed that is requested following an exchange of ink cartridges, and air bubbles in the recording head can be discharged.